Brain Function Monitoring
A More Complete Picture Starts with More Complete Data
Brain function monitoring provides real-time insight into a patient's depth of anesthesia. To facilitate timely assessment of patient status, Root® with SedLine® provides the Patient State Index (PSI™), a process EEG parameter that provides information about a patients response to anesthesia.
Accurately assessing level of sedation in ICU patients has been a challenge. The effectiveness of using physiologic measures such as vital signs or response to stimulation can be compromised by the presence of other drugs. Monitoring sedation through the use of sedation assessment scales is limited to single-point measures in time. Further, the accuracy of sedation assessment scales may be compromised by subjectivity and inter-rater variability.
Practice guidelines suggest that objective measures of brain function (e.g., auditory evoked potentials [AEPs], Bispectral Index [BIS], Narcotrend Index [NI], Patient State Index [PSI], or state entropy [SE]) be used as an adjunct to subjective sedation assessments in adult ICU patients who are receiving neuromuscular blocking agents, as subjective sedation assessments may be unobtainable in these patients (+2B).2
Researchers have recommended that EEG monitoring be used to monitor nonconvulsive seizure activity in adult ICU patients with either known or suspected seizures, or to titrate electrosuppressive medication to achieve burst suppression in adult ICU patients with elevated intracranial pressure (+1A).3
Correlation Between PSI and Ramsay Sedation Scale (RSS)
A strong correlation between the PSI values and the Ramsay Sedation Scale (RSS) as demonstrated in a study2 identifies the opportunity to effectively manage sedation and analgesia in an objective, consistent manner across the continuum of care, especially in intubated, ventilated ICU patients. Further, changes in the PSI in response to clinical events may provide an early warning for patient safety as highlighted in a recent review of sedation measures in the ICU4.
By continually monitoring a patient's level of sedation, this may help add value to patient care by contributing to:
- > Improved patient safety
- > Optimized medication levels
- > Reduced ventilator days
- > Reduced cost
“A total of 349 RSS assessments were made during the course of the study. The mean PSI score (± 95% CI) for each of the RSS values was plotted (Figure 1). The correlation coefficient equals -0.98 indicating a strong relationship between the PSI and all levels of RSS5.”
"We need much better monitors of the brain and to use these monitors of the brain. I think this is the advantage that SedLine brings to you is that it doesn't just look at one little area of the brain. It looks at both sides of the brain."
Michael Ramsay, MD
Chairman, Dept. of Anesthesiology
Baylor University Medical Center
Ventilated ICU patients
It is a challenge to properly sedate ventilated patients in the ICU. As a result, most patients are over-sedated, meaning they spend more time than necessary on the ventilator, prolonging their stay in the ICU, exacerbating the risk of complications and increasing the cost of their care. The goal is to more tightly control sedation, thereby minimizing negative clinical and financial outcomes.
"As this technology gets better, as we have with the SedLine - easy to apply, fewer artifacts - this now becomes a functional tool to correctly control our sedation levels and reduce costs in our ICU, reduce morbidity in our ICUs and reduce stay in our ICUs."
Michael Ramsay, MD,
Chairman, Department of Anesthesiology
Baylor University Medical Center, Dallas, TX
- 1 Prichep LS, Gugino LD, John ER, et al. The Patient State Index as an indicator of the level of hypnosis under general anesthesia. Br J Anaesth. 2004,92:393-399. Available online at http://bja.oxfordjournals.org/cgi/content/full/92/3/393.
- 2,3 Clinical Practice Guidelines in adult patients in Intensive Care Unit Am J Health-Syst Pharm—Vol 70 Jan 1, 2013
- 4 Sessler CN, Grap MJ and Ramsay AE. Evaluating and monitoring analgesia and sedation in the intensive care unit. Critical Care 2008, 12(Suppl3):S2. Available online at http://ccforum.com/content/12/S3/S2.
- 5 The Patient State Index Correlates Well with the Ramsay Sedation Score in ICU Patients. Ramsay M.A., Huddleston P., Hamman B. Tai S., Greg M. Anesthesiology 2004; 101: A338.
- Nguyen NK, Lenkovsky F, and Joshi GP. Patient State Index during a cardiac arrest in the operating room. Anesth Analg. 2005,100:155-7. Available online at http://www.anesthesia-analgesia.org/cgi/content/full/100/1/155.
- Crippen D. Bispectral Index: Is It Ready for Prime Time in the ICU? Available online at http://www.medscape.com/viewarticle/471955. Posted March 24, 2004.
- White PF, Tang J, Ma H, et al. Is the Patient State Analyzer* with the PSArray a cost-effective alternative to the Bispectral Index Monitor during the perioperative period? Anesth Analg. 2004,99:1429-1435. Available online at http://www.anesthesia-analgesia.org/cgi/content/full/99/5/1429.
- Kurup V, Ramani R, Atanassoff PG. Sedation after spinal anesthesia in elderly patients: a preliminary observational study with the PSA-4000. Can J Anaesth. 2004 Jun-Jul;51(6):562-5. Available online at http://www.ncbi.nlm.nih.gov/pubmed/15197118.
- Schneider G, Mappes A, Neissendorfer T, Schabacker M, Kuppe H, Kochs E. EEG-based indices of anesthesia: correlation between bispectral index and patient state index? Eur J Anaesthesiol. 2004 Jan;21(1):6-12. Available online at http://www.ncbi.nlm.nih.gov/pubmed/14768917.
- Schneider G, Gelb AW, Schmeller B, et al. Detection of awareness in surgical patients with EEG-based indices-bispectral index and patient state index. Br J Anaesth. 2003 Sep;91(3):329-35. Available online at http://bja.oxfordjournals.org/cgi/content/full/91/3/329.
- Chen X, Tang J, White PF, Wender RW, Hong M, Sloninsky A, Kariger R. A comparison of Patient State Index and Bispectral Index Values during the perioperative period. Anesth Analg. 2002;95:1669-1674. Available online at http://www.anesthesia-analgesia.org/cgi/content/full/95/6/1669.
- Hausman, L., Processed electroencephalographic changes associated with hypoglycemia during the resection of an insulinoma. Anesthesiology 2002; 97(4):1013-1014. Available online at http://journals.lww.com/anesthesiology/Fulltext/2002/10000/Processed_Electroencephalographic_Changes.40.aspx.
- Drover DR, Lemmens H, Pierce ET, Plourde G, Loyd G, Ornstein E, Prichep LS, Chabot RJ, John ER, Gugino LD. Patient State Index (PSI): Optimization of delivery and recovery from propofol, alfentenil and nitrous/oxide anesthesia. Anesthesiology. 2002; 97(1):82-89. Available online at http://journals.lww.com/anesthesiology/Fulltext/2002/07000/Patient_State_Index__Titration_of_Delivery_and.12.aspx.
- John ER, Prichep LS, Kox W, et al. Invariant Reversible QEEG Effects of Anesthetics. Conscious Cogn. 2001;10:165-183. Available online at http://www.ncbi.nlm.nih.gov/pubmed/11414713.
- Gugino LD, Chabot RJ, Prichep LS, John ER, Formanek V, Aglio LS. Quantitative EEG changes associated with loss and return of consciousness in healthy adult volunteers anesthetized with propofol or sevoflurane. Br J Anaesth. 2001;87(3):421-428. Available online at http://bja.oxfordjournals.org/cgi/content/full/87/3/421.
- Prichep LS, John ER, Gugino LD, Kox W, Chabot RJ. Quantitative EEG assessment of changes in the level of sedation/hypnosis during surgery under general anesthesia. In: Jordon C. Memory and Awareness in Anesthesia IV. London: Imperial College Press, 2000:97-107. Available online at http://www.worldscibooks.com/medsci/p190.html.
Caution: Federal (USA) law restricts this device to sale by or on the order of a physician. See instructions for use for full prescribing information, including indications, contraindications, warnings, and precautions.